Steel-retainer for hammer-drills.



R. H. WILHELM. STEEL RETAINER ran HAMMER DRILLS.

APPLICATION FILED JULY 21. 19 6. 1,217,378.

l ugsezm m ne)... Fig. 3

BY ATTORNEY UNITED STATES PATENT OFFICE.

RUSSELL H. WILHELM, OF EASTON,- PENNSYLVANIA, ASSIGNOB TO INGEBBOLL-RAND COMPANY, 01? J CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

STEEL-RETAINER FOR HAMMEB-DRILLS.

Specification of Letters Patent.

, Patented Feb. 27, 1917.

Application filed July 21, 1918. Serial 80. 110,461.

. Retainers for I-laxnmerJJrills, of which the following is a specification.

This invention relates to steel retaining mechanism for hammer drills.

()n hammer drills, particularly of the hand type, it is necessary to provide a device which can be utilized to engage the drill steel to move it with the drill when it is desired to remove the steel from or loosen it in the drilled hole. In drills of the type in question the steel is usually of a uniform cross section, except that it is provided with a collar which abuts against the forward end of the front head of the drill and deter:

mines-the position of the steel therein. Va-

rious devices have been devised to engage and hold the drill steel when desired these generally consisting of a yoke pivoted in some way on the front head of the drill and arranged to be held more or lessiirmly in contact with the steel during the operation.

. tion and retained there without being held.

With this object in view I have devised a steel retaining mechanism, a practical embodiment of which is shown in the accompanying drawings, in which Figure 1 shows a plan view of the front head of a drill provided with my steel retaining device in operative position,

Fig. 2, a side elevation of the same, and Fig. 3, a side elevation showing the steel retaining mechanism in inoperative position.

In the drawin is shown the front head 1 of an ordinary rilling machine, not shown, in which is mounted the drill steel 2 provided with a collar 3-which abuts against the front end of the front head 1 and determines the position of the steel therein. (in the lower side of the front head 1, out of alineposition a ment with the steel 2, are oppositely laced lugs l projecting from the fronthea these being of cylindrical contour on their lorward sides 5 but being flattened on their rear faces to produce fiat surfaces 6. Pivoted on these lugs is the steel retaining mechanism, which consists of a yoke 7 having an upwardly rojecting portion 8 provided with a slot 9 at apted to fit over the steel 2 but not sufficiently wide to permit passage therethrough of the collar 3. Projectingv rearwardly from the oifset portion 8 of the yoke are side arms 10 which are provided at their rearward ends with heads 11, the rearward faces of the heads 11 being provided ,with semi-circular depressions 12 ada ted to fit and rotate on the forward roun ed sides 5 of the lugs 4. Sliding in bores 13 passing.

are retaining bolts 14, the heads 15 of which project downwardly and are provided on their forward sides with flat surfaces 16 adapted to contactwith the flat surfaces 6 of the lugs 4 when the steel retaining mechanism is in its 0 erative position as shown in Fig. 2. The orward ends of bolts 14 are provided with nuts 17 and springs 18 are interposed between the nuts :17 and the forward sides of the yoke sidearm heads 11 so that there is a constant resilient pressure tending to force heads 11 oi the side arms 10 and heads 15 of the retaining bolts 14 together.

The operation of the present device will be easily understood from the above description. When the drill is in operation the steel retaining device is 'moved mtothe position shown in Fig. 2 and'held there by reason of the contact of the flat surfaces 8 and 160i the lugs 4 and the steel retaining" mechanism. When it is desired to remove the steel from the drill the yoke 7 is grasped by the hand of the operator and moved to the position shown in Fig. 3, in which position the flat surfaces 16 are in contact with the rounded surfaces of the lug 4 and havev no tendency to movd the steel retaining mechanism into operative position so that the steel retaining mechanism will remain in this position until moved into operative in by hand.

It is to eat showing and description discloses onl; one specified modification of this invention. other forms and modifications are included understood that while the preswithin the spirit and scope thereof, as expressed in the appended claims. WhatI claim is:

,1. In combination with a drilling tool having a front head and a collared drill steel, operatively mounted in said front head, lugs on opposite sides of said front head, and a steel retaining mechanism trunnioned on said lugs, said steel retaining mechanism comprising a yoke having a steel engaging slot and side arms contacting with and bearing on the forward sides of said Y lugs, retaining bolts slida'bly mounted in said side arms and having portions engaging the rear sides of said lugs, and means for Iresiliently drawing said yoke and retaining bolts together.

2.1m combination with a drilling tool' having a front head and a collared drill steel .opcratively mounted in said front head, lugs on opposite sides of said front head, and a steel retaining meehanlsm trunnioned on 1 said lugs, said steel retaining mechanism comprising a yoke having-a steel engaging slot and side arms contacting with and bearing on the forward sides of said lugs, re-

taining bolts slidably mounted in said side arms and having portions engaging the rear sides of said lugs, means for resiliently drawing said yoke and retaining bolts together and means for holding said yoke in operative position. 3. In combination with a drilling tool having a front head and a collared drill steel operatively mounted in said front head, lugs on opposite sides of said front head, and a steel retaining mechanism trunnioned on said lugs, said steel retaining mechanism comprising-a yoke having a steel engaging slot and side armscontacting with and bearin on the forward sides of said lugs, retalning 'bolts slidably mounted in said side arms and having portions engaging the rear sides of said lugs, means for resiliently drawing said yoke and retaining bolts together and means for holding said yoke in operative position comprising flattened surfaces on said In arranged to contact with surfaces on sai steel retaining mechanism when said yoke is in operative position.

In testimony whereof, I have hereunto set my hand.

RUSSELL H. WILHELM.

Witnesses:

- A. H. TAYLOR, F. W..Ropnn-r. 

